Fokker-Planck approach to molecular motors

Most of the known molecular motors are fueled by ATP hydrolysis. In vivo these machines work near their enzyme saturating regime and the speed is so fast that finer details are not experimentally observable. Molecular motors are usually modelled by overdamped Langevin equations with a two-state flashing potential where transition rates are related to the random hydrolysis process. We will present a theoretical analysis of this process, which shows that it can be approximated by a white-noise process. This implies that a Fokker-Planck equation can be a useful tool to study molecular motors in the ATP saturating regime. As a practical application we present a detailed study of the molecular F1-ATPase rotatory motor with a discussion on its energetics. Theoretical predictions are compared satisfactorily with experimental data in the appropriate limits, which are well delimited